docs: def list_chunks(l, n):
      """Yield successive n-sized chunks from l.
  
      import pprint
      pprint.pprint(list(chunks(range(10, 75), 10)))
      [[10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
       [20, 21, 22, 23, 24, 25, 26, 27, 28, 29],
       [30, 31, 32, 33, 34, 35, 36, 37, 38, 39],
       [40, 41, 42, 43, 44, 45, 46, 47, 48, 49],
       [50, 51, 52, 53, 54, 55, 56, 57, 58, 59],
       [60, 61, 62, 63, 64, 65, 66, 67, 68, 69],
       [70, 71, 72, 73, 74]]
  
      """
      for i in xrange(0, len(l), n):
          yield l[i:i + n]